Matthew Celenza’s departure to launch own firm comes as wirehouses struggle to keep top talent

Merrill Lynch has lost to the independent ranks a broker who managed $1 billion, as Wall Street’s biggest brokerages continue to struggle with keeping top talent.

The broker, Matthew Celenza, said he resigned from Merrill on Friday to launch his own wealth-management firm, known as Boulevard Family Wealth, in Beverly Hills, Calif. Mr. Celenza had been with Merrill for six years and was a part of its private banking and investment group, the team of brokers who focus on clients with $10 million or more in assets.